Walkie Talkies for emergencies?

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stuartjmz

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#303546 17-Feb-2023 17:47

I've seen some helpful replies to a related thread on this at r/newzealand, but figured it couldn't hurt to ask here. Having lost cell coverage after Gabrielle, would walkie talkies be a practical backup option here in Hawke's Bay? If not, why not, and if yes, which brands, wattage etc? Just looking for basic 'keep in touch' capability in greater Hastings area in the event of another cell network outage.

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#3038298 17-Feb-2023 18:03

Depends on what you're looking at. Anything decent will require a license legally.

You can get basic UHF transceivers for little $$ but these are generally only 3-10km LOS range depending on wattage but some do have access to repeaters, so long as the repeaters survive whatever disaster strikes, you can get extended range.

@Blakjak is my go to for radio info :D

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antoniosk

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#3038299 17-Feb-2023 18:07

Walkie talkies tend to be point to point solutions, as one big party line. Useful for about 1000m radius in a relatively unobstructed area. You also need people to be disciplined and not hog the airtime.

Over a wider area, radio telephones are better as they use a radio network with repeaters. There are commercial services - VITAL runs the biggest one in nz, born from the ashes of fleetlink and teamtalk - but that costs money (monthly subs, kit is about $2k per device etc, plus batteries need to be kept charged. I was involved in these very early in my career but have no idea what things are like now.

I always wondered if there was a way to adhoc network smartphones together into a quasi area network and shift every device to push to talk mode, but then remembered batteries suck….

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stuartjmz

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#3038302 17-Feb-2023 18:10

Thanks! 3-10km would be fine for our purposes I think. Not looking to communicate far afield. Does LOS mean that you literally have nothing in the way of a line of sight? If I'm on one side of Hastings and the other handset is 3.5km away on the other side, would they work, or would urban buildings impede reception?

stuartjmz

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#3038304 17-Feb-2023 18:12

antoniosk: Walkie talkies tend to be point to point solutions, as one big party line. Useful for about 1000m radius in a relatively unobstructed area. You also need people to be disciplined and not hog the airtime.

Over a wider area, radio telephones are better as they use a radio network with repeaters. There are commercial services - VITAL runs the biggest one in nz, born from the ashes of fleetlink and teamtalk - but that costs money (monthly subs, kit is about $2k per device etc, plus batteries need to be kept charged. I was involved in these very early in my career but have no idea what things are like now.

I always wondered if there was a way to adhoc network smartphones together into a quasi area network and shift every device to push to talk mode, but then remembered batteries suck….

That's very helpful, thanks. Looks like I might be saving my money.

xpd

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#3038312 17-Feb-2023 18:26

stuartjmz:

Thanks! 3-10km would be fine for our purposes I think. Not looking to communicate far afield. Does LOS mean that you literally have nothing in the way of a line of sight? If I'm on one side of Hastings and the other handset is 3.5km away on the other side, would they work, or would urban buildings impede reception?

Pretty much.... theyre good for building sites etc, but across town is another story. You'd want 5W to be safe even over 3.5km.

Something along the lines of https://www.jaycar.co.nz/gme-5w-uhf-transceiver-tx6160x/p/DC9054?pos=4&queryId=48e0f5fab2fdf8beafcef4b59582268f

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stuartjmz

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#3038316 17-Feb-2023 18:31

xpd:

stuartjmz:

Thanks! 3-10km would be fine for our purposes I think. Not looking to communicate far afield. Does LOS mean that you literally have nothing in the way of a line of sight? If I'm on one side of Hastings and the other handset is 3.5km away on the other side, would they work, or would urban buildings impede reception?

Pretty much.... theyre good for building sites etc, but across town is another story. You'd want 5W to be safe even over 3.5km.

Something along the lines of https://www.jaycar.co.nz/gme-5w-uhf-transceiver-tx6160x/p/DC9054?pos=4&queryId=48e0f5fab2fdf8beafcef4b59582268f

Very helpful - that handset is at the top end of what I was prepared to pay, so if I get some extra work, I might consider getting a couple on the principle that they just might come in handy, and won't take up much space in the go bags anyway

MikeAqua

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#3039308 20-Feb-2023 10:45

Every post-apocalyptic movie or series I have seen suggests communicating via radio will end badly.

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BlakJak

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#3040695 22-Feb-2023 21:16

Yeah, don't believe what you see in the movies.

Basically - who do you want to talk to?

UHF PRS radios (470mhz) will give you a short range - anything from several hundred meters to a few kilometers, depending on the model (the tiny/cheap ones will be on the shorter side). Max power output is usually 5W with an external antenna can give you tens of kilometers if the geography is favourable. Line of sight is majorly important; suburban Wellington will be patchy as all heck because of the geography.

If the person you want to talk to doesn't also have a radio | have it on with the volume up | have it in earshot | have line of sight to you, then you can't talk to them.

NZ doesn't really have a strong culture of common calling channels and so-on, as compared to (say) outback Australia, where CB radio (26/27Mhz) can give you quite decent range, due to the lower frequency and better propogation (line of sight less of an issue because the radio signal bounces off the atmosphere and comes back, instead of UHF which just carries on into space, no reflections).

Which brings us back to, what do you want to use them for?

If you have a neighborhood arrangement for channels and an agreement to listen, then go for it.

Remember you've got to think about batteries, or power supply, and if they're not used and cycled periodically they'll not be very good after a few years.

If you want something that'll let you reach beyond your local neighborhood in case of emergency, you could try 26Mhz CB (note they are generally vehicle or fixed-base mounted and have a larger antenna requirement than UHF PRS), or for a better result, get your Amateur Radio License which opens up a whole bunch of new options. I've used my amateur radio gear in an 'emergency' precisely once - when I got mugged and the thief took my cellphone, but left the radio behind. A call over a local repeater resulted in a quick 111 call and the cops nabbing the offender within about 20 minutes. I got my phone back (in pieces). :)

www.nzart.org.nz will give you information about amateur radio in NZ; if you're in Auckland there's at least one decent radio club in each major district (West, Central, South, North Shore) and in Wellington I recommend the Wellington VHF Group (vhf.nz) That's for real, useful radios. "Walkie Talkies" - great for talking close to home, or with a relative if you need to go for a walk, that sorta thing. But not a real alternative to decent HF radio or satellite based services.

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stuartjmz

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#3040697 22-Feb-2023 21:24

BlakJak: Yeah, don't believe what you see in the movies. ... "Walkie Talkies" - great for talking close to home, or with a relative if you need to go for a walk, that sorta thing. But not a real alternative to decent HF radio or satellite based services.

Thank you. My scepticism about marketing claims was exactly why I asked here, and I'm glad that I did. Your reply adds weight to the similar replies above. This thread has convinced me that decent quality walkie talkies could be a nice 'optional extra' for our go bags in the event we have to flee and end up somewhere without cell coverage (since we would then be in comparatively close proximity to each other) , but are not an urgent 'must have'.

BlakJak

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#3040718 22-Feb-2023 23:13

Decent quality 5w UHF handhelds (PRS) that can use AA battery packs as well as a rechargable are the way I'd go, if money isn't a huge issue. They can also be useful for convoys or when you go on holidays or other adventures. Helpful to use them occasionally to keep your hand in and know what to expect. You should agree on primary and alternate channel numbers that you'll use routinely so if you get separated you know where to look.
We used UHF handhelds in my car club days and they were excellent value.
In an emergency kit situation you want to be able to use off the shelf, long-shelf-life readily available batteries.
LandSAR keep their radios with rechargable batteries fitted, on chargers which monitor their battery health and they exercise with them often enough to keep them cycling. But when they go into the field the AA packs are their spares for when the rechargables fail.

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stuartjmz

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#3040719 22-Feb-2023 23:18

BlakJak: Decent quality 5w UHF handhelds (PRS) that can use AA battery packs as well as a rechargable are the way I'd go, if money isn't a huge issue.

Thanks again. II've been looking at GME 5W models, and am planning to put some money aside until I can buy them. When I do, I'll definitely follow your suggestion to practice on channels we select often enough to know what we're doing.

Dreamerz

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#3046044 5-Mar-2023 15:30

Just found this thread.

I live in an area that was cut off from all power and cell coverage for around a week, I have been working on an emergency coms system before this happened but had yet to deploy anything.

Its not voice, its an opensource messaging using LoRa Radios in a mesh network (not LoRawan) and a cellphone (or optionally standalone), point to point range varies a fair amount my max was 166kms at 160mw (stated likely closer to 100mw) output power with a small omni antenna. Repeaters are easy to deploy and can run off small 5w solar panels if you add GPS for accurate time keeping requirements go up to around 8w

If anyone in the Hawkes bay/Gisborne area is interested send me a DM

timmyh

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#3046046 5-Mar-2023 15:48

Another trend coming along is Satellite comms service built into mobile phones. The iPhone 14's that came out from Sept last year have a service that allows an emergency message to be sent from a phone via satellite, but it needs to be enabled country by country presumably due to interconnect to be able to relay messages to the local emergency service. I would expect that this same feature to come from other mobile phone vendors. Over time this service could expand from just text messages to voice messages to live calls, but not sure.

stuartjmz

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Master Geek

#3075281 12-May-2023 05:19

In the end, economic realities led me to buy 2 Digitech DC-1068s from Jaycar. They should be adequate for the go bag/emergency use I had in mind. The device I would have bought had money been no object, the GME TX6600PRO, costs 30% per unit than I paid for the 2 devices I ended up buying, sadly not justifiable in my circumstances. One of the things that had me keen on the GME was its longer antenna - 150 mm versus 70mm on the Digitechs. Are antennae strictly proprietary and exclusive, or would any SMA male antenna in the right frequency range work with my devies? If so, would it be worth buying longer antennae to perhaps get 1-2 extra km of reliable range?

BlakJak

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#3075300 12-May-2023 07:50

Any antenna with the right fitting and tuned for the right frequencies will work. With "rubber duck" antennas as in the top of a handheld radio there isn't a huge difference between antennas unless you're changing to something with significantly different length or gain. Switching for another fairly short antenna is likely to make only marginal difference.

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